Objectives: Despite utilization of available means for cardioprotection during cardiac surgery, myocardial injury still occurs. Further improvement of cardioprotection is therefore necessary. Remote ischemic preconditioning (RIPC) is an easy and non-invasive method. Laboratory research has shown promising results regarding myocardial survival during open heart surgery, but the clinical value of RIPC is still largely unknown. The investigators hypothesize that RIPC before coronary artery bypass grafting (CABG) reduces the incidence of postoperative atrial fibrillation (POAF).